Trees

In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants to compete for sunlight. In looser senses, the taller palms, the tree ferns, bananas and bamboos are also trees. Trees tend to be long-lived, some reaching several thousand years old. The tallest known tree, a coast redwood named Hyperion, stands 115.6 m (379 ft) high. Trees have been in existence for 370 million years. It is estimated that there are just over 3 trillion mature trees in the world.

In Doctor Who, most writers cannot see the forest for the trees, and thus season long arcs tend to be a bit shit. RTD was exceptional in that he couldn't see thetreesfortheforest. As if to further accentuate this point, most episodes that feature trees in Doctor Who are pretty shit. Here are some examples of trees ruining your day:

Trees attempt to blast Earth's atmosphere with a giant layer of oxygen in order to burn out a word-ending solar flare. Hey, don't blame the trees, they never took science class and don't understand how basic thermodynamics works. In the Forest of the Night was prety shit.